Compressor



June 11, 1935# BfBoGosLoWsKY 25004563 COMPRESSR Filed June 2s, 1951 ssheets-Sheet 1 I N VEN TOR. Qr/S ogos/o wsky A TTORNE Y.

June 11, 1935. B, BOGOSLOWSKY 2,004,563

COMPRES SOR Filed June 23, 1931 3 Sheets-Sheet 2 1F99; f l

INVENTOR. or/s ogos/asky A TTORNEY.

innemen! June 11, 193s 2,004,563 COMPRESSOR Boris Bogoslowsky, Bri

by mesne Fitchburg, Mass Application June 23,

4 Claims.

is a compressor and more par- 5 weight.

A further object of the invention is a compressor which will produce uidunder the desired pressure, but at a relatively low velocity.

An important feature of this invention and one I have, as a sequentslight loss in pressure. This is accompanied by an expansion, and thesetwo factors coupled with the necessary change of direction inpassingthrough the labyrinth cause the retardation of the pressure tosuch extent as to practically eliminate the escape of pressure from thepockets between the respective vanes.

' through passages center dgepoi't, Conn., assignor, assignments, toArnold C.

Dickinson,

1931,'seria1 No. 546,274 (C1. 23o-152) Another important feature of thisinvention resides in the fact that the rotor of my compressor 'is ahollow or cored rotor and this rotor is provided with a relatively.large number of radivanes relatively small pockets in'which compressiontakes place. With this construction, the y vanes follow one another insuch rapid sequence and the pressure between successive pockets isgraduated so linely that the pressure will be held in any one pocket byapproximately the same pressure in the next succeeding pocket. In otherlwords, the building up of the pressure in the successive pockets is sogradual that the pressure in each pocket substantially the pressurenates friction thereby permitting the device to be run at speeds whichwould otherwise be wholly impractical. VTo further minimize friction,the vanes are made quite thin and may be fabricated from material whichis itself a lubricant.

I have referred to the operation of the vanes in webs in the rotor. Therotor is in the main built up of a series of radial webs providingthere-l between chambers, so that the whole rotor is in eiectskeletonized. The chambers communicate with the center of the rotorwhich is hollow and open at its ends and the chambers are also open attheir ends to the atl 35 mosphere, so that as the rotor is turned athigh there `will e a constant circulation of cooling fluid through thecenter of the rotor out 4 wardly through the chambers and from thechambers to the outer atmosphere in the event that an air cooledstructure is desired. If a water cooled structure is desired, the endplates of thecasing may be connected with a suitable water outlet andwater may be fed through the hollow A to produce the liquid.

The present invention may, in practice, be incorporated in a singlestage compressor or may operate upon multiple stage principles. If asingle stage compressor is desired, the casing may 50 have have a singleeccentricity with respect to the rotor and may in. effect becylindrical. I1 a A multiple stage compressor is desired, that portionof the casing which .coacts with the vanes will have a multipleeccentricity'as will be here- 55 l circulation of the cooling of thecasing, as is made in theform of a casting of inafter more fullyexplained, there being an intercooler interposed between the respectiveeccentricities for reasons which will be fully understood.

The invention embodies further additional important features which willbe apparent from the following detailed description when read inconjunction with the appended claims and the accompanying drawings.

The accompanying drawings illustrate different practical embodiments ofthe invention, but the constructions therein set forth are to beunderstood as illustrative, only, and not as dening the limits of theinvention.

Figure l.shows a single stage compressor em' bodying the presentinvention. The rotor and its shaft are shown in elevation, but thecasing is shown in section in the plane of the line I-I of Figs. 2 and3.

Figure 2`is a the lines 2-2 of Figures l and Figure 3 is a sideelevation shown in Figs. 1 and 2. Figure 4 is an end view of thestructure of Figure 3.

Figine 5 is a packing disks.

Figure 6 is an edge view ofthe disk shown in Figure 5.

Figure 'l is an edge view of one of the smaller packing disks of therotor. `Figure 8 is a diagrammatic view illustrating the manner in whichthe invention may be embodied in a multistage compressor.

Figure 9 is a view similar to-Figure 1 but show-- ing a modified form oflabyrinth packing.

Figure 10 shows one of the labyrinth packing rings of the casingillustrated in Figure 9. i

Referring iirst to the single stage compressor as shown in Figs. l to 7,inclusive, the casing or stationary part of the compressor comprises acentral portion I, which is cylindrical and is eccentric with respect tothe two end portions 2 which are also respectively include end plates 3which have axial bearings 4 in which is supported the shaft 5 of therotor 6. With this arrangement, the rotor 6 is mounted to rotatecoaxially with the end portions 2 of the casing and all parts of therotor are. coaxial with one another and with the end portions 2 of thecasing, but that portion of the rotor which operates within the centralportion I of the casing 'is eccentric with respect to said portion Iclearly shown in Fig. 2. This said central portion of the rotorsdesignated by the reference character 1. The central portion 1 of therotor is preferably cylindrical form. tightly fitted upon the shaft 5which is hollow and said casting 1 is coredout, so that its'crosssection resembles the spokes of a wheel, as shown in Figure 2. Theseso-called spokes constitute in eiect webs 8 which support the peripheralcylindrical wall of the casting.

transverse section in the plane of 3. of the apparatus face view of oneof the labyrinth 4 Between the respective webs, the casting is hollowand constitutes a plurality of chambers 9 which extend from one end tothe other of the casting. On the Opposite ends of the casting 1 aremounted anges and these flanges are each composed of a plurality ofpacking disks. These packing disks lare of two sizes alternatelypositioned with reclearly shown in Figure designated Ill' and one spectto o ne another as 1. The larger disks are of them is shown in Figs.v 5and 6, the smallerthe Vother of the a radial direction.

cylindrical. The end portions 2 torily hold the pressure.

disks are'designated I I and one of them is .shown in Figure 7. Thesedisks are fastened iirmly to the ends of the casting 1, by means ofscrews or bolts I2 and said disks are provided with openingscorresponding in shape and'placement to the chambers 9 of the rotor sothat these chambers will extend uninterruptedly from one end to rctor. Y

The central portion I of the casing is in the form of a casting I4provided on its exterior with radiating fins if the pump is to be aircooled or jacketed if the pump is to be water cooled. This casting is ofsubstantially the same axial length as the casting l1 and interposedbetween the Aends of the casting I4 and the end plates 3 are rings I5and I6, of which the rings I5 are relatively narrow, while the rings I6are. relatively wide. These several rings I5 and I6- are alternately'exposed according to size and screws or bolts I1 extend through the endplates and into the casting I4 to secure the parts of the casingtogether. l

As clearly shown in Fig. l, the large disks III are juxtaposed with thenarrow rings I5, while the small disks II are juxtaposed with the widerings I6, so as to produce in effect a castellated cross section. It isimportant to this inventicn, however, that none of the disks contactwith any of the rings and accordingly the rings I5 and the disks II aremade of the same thickness, while the disks I0 and the rings I6 are madeof the same thickness as one another, but of a lesser thickness, say oneor two thousands of an inch less than the thickness of the rings l5 anddisks II. Thus, while all the rings and disks intert as shown in thisfigure, they do so without contact in an axial direction and suflicientclearance is also allowed to preclude their contact in The shaft 5 isalso mounted so that it will not have axial movement and it thereforefollows that the rotor is adapted to turn without any part thereof thusfar described coming in contact through the bearings 4.

Formed in each of the webs 8 of the rotor is a pocket I8 and in each Vofthese pockets isposi- I9 which, as the rotor is turned, is with andfollow the inner casting I 4. It is pertinent here to note that thereare preferably as many webs provided as the size of the structure will nvanes as possible under the circumstances. These vanes aretherefore madeas thin as the work which they are required to do will -permit and arebylpreference` constructed from some self lubricating material orcomposition embodying as with any part ofthe casing except' allow, so asto obtain as many one of its elements some lubricating substance,

such as graphite, although the invention is not limited in this regard.Experiments made with graphited bakelite and textolite have given verysatisfactory results although other materials may be employed withoutdeparting from this inven-l tion. The vanes are mainly guided by thepockets I8 of the rotor, but it will be noted from Figure l that theinnermost disks-I0 are also provided with radial channels 2| of thepockets I8 and serve to support and guide the opposite ends of thevanes. This is highly important as it serves vanes and the innermostdisks I0 and eliminates side pressure or axial pressure on the vane.Without this structure, it is'impossible to satisfaclThe vanes workingin which register with the ends as a packing between the the channels,however, are highly edicient for the purpose stated.

In the single stage compressor shown in Figs. 1-7, the casing isprovided with an inlet 22 and an outlet 23. The inlet is positioned atsubstantially the point of greatest 4distance between the rotor and thecasing, while the outlet is positioned at approximately the shortestdistance between the rotor and the casing. Thus, if the rotor is rotatedin a clockwise direction in Fig. 2, air will pass into pockets 24between the consecutive vanes and as the air is carried along in thesepockets, it will be compressed until it reaches its maximum compressionadjacent the outlet 23 where it will be discharged. It will be noted,moreover, that a passage or channel 25 extends from the inlet 22 in aretrograde direction along the inner surface 20 of the casing. 'Ihepurpose of this channel is to permit air to enter the pockets 2Spractically as soon as a minus pressure is produced therein. Thus, thepockets 26- are adapted to be fed with air if this is the iluid to becompressed, from the time they overlap the channel 25 until they pass bythe inlet 22 and from that point to the outlet compression takes place.

I have referred to the use oi as many pockets as convenient under the'circumstances and I prefer to have these pockets small so as topermitof a considerable number of them. The purpose of this arrangement is toprovide a relatively gradual stepping up of the pressure between the ioutwardly through the ends consecutive pockets, so that the pressure inany one pocket willserve as a pressure buffer against the escape ofpressure from the next preceding pocket. As a resulto this arrangement,it is found unnecessary to have an absolutely leakproof joint betweenthe outer edges of the vane and the surface of the wall 2li.Furthermore, as hereinbefore pointed out, with the labyrinth packingwhich I have described as formed by the disks i@ and ii and rings i5 andit, leakage at the ends of the pockets 2d by escape or pressure throughthe joints between the nanges of the rotor and the casing is negligible.I have found that this pressure in order to escape must change directionrapidly a great many times. At each change of direction, there isretardation of the new and this coupled with skin friction has beenfound by me to produce such emcient retardation that escape of pressureis negligible as to constitute in efect an actual packing through theuse of the fluid itself, despite the rfact that there is no actualcontact between the movable and stationary parts.

It will be-noted from Figure 2 that the shaft 5 is hollow and that eachof the chambers scommunicate with the interior of the hollow shaftthrough passages 26 while from Figure 1 it will be noted that the endplates are cut out or skeletonized as shown at2`l. Accordingly, when therotor is operated at high speed, the air within the hollow shaft willpass through the passages 26 and of these passages and through theopenings 21, so that there will be a circulation of air within the rotorwhich will serve as a cooling medium. It will be further noted that byskeletonizing the rotor as shown, all of the Walls thereof arerelatively thin so that `any heat generated can be readily carried on bythe iiow of cooling fluid through the interior of the rotor as stated.Air cooling is preferred, but, if desired, water or other cooling liquidmay be circulated without departing from this invention.

In the invention, as thus far described, the apparatus has been shown'as a single stage compressor. In Fig. 8, however, I havediagrammatically illustrated the adaptation of the present invention toa multiple stage compressor. In this ngure, the structure issubstantially the same as described in the preceding iigures'with theex- -ception of the cross sectional shape of the casting ||4 whichcorresponds to the casting `I4 and with the further difference thatthere is a variation in the position of the inlet and outlet |22 and|23,

tercooler through the inlet 2S and passed through.4

a further compression stage until it is discharged through the outlet|23. The operation will be clearly apparent from the foregoingdescription of the invention. l'I'he' packing operation of the vanes andthe formation of the rotor structure is the same as in the precedinggures and the opposite ends of the casing are cylindrical to 4cooperatewith the cylindrical rotor to produce the 4packing as hereinbeforedescribed.

The apparatus of this invention has been referred to primarily as acompressor for compressing air, gas, or other uids, but I am of courseaware that it may be operatedif desired as a vacuum pump.

The apparatus described embodies numerous advantageous features. Thehollow rotor with its relatively thin walls permits of proper cooling,and this cooling applies not only to the maincasting of the rotor, butalsoto the cooling ofthe labyrinth packing disks. These packing disks,as well as the cooperating rings in effect, a laminatedconstructionwhich permit the parts to be readily assembled and also permits me tomake the main castingof the casing in one piece without necessitatingseparable diametric sections. commercial standpoint and from thestandpoint of operation. l The rotor of this invention is extremelylight as compared with prior practice and its eciency surpasses by manytimes any other compressor construction heretofore suggested. Withreference to the multistagecompressor feature 'of this inventio it willbe apparent that the invention provides in one unit for the use of asingle hollow rotor and a single stator in a multiple stage compressoror vacuum pump.

In the foregoing packing in both cases is built up in the form oflaminations by superimposing disks and Arings as described. It is withinthe purview oi this invention, however, to produce labyrinth packingwithout laminations and in Figs. 9 and 10, such an arrangement is shown.In these figures, the anges 36 of the rotor instead of being built up bythe laminating disks I0 and are made in the form of solid pieces securedto the main casting of the rotor by means ofscrews i2.. The peripheriesof these flanges are circumferentially channeled to produce acastellated cross section. The central portion and the end plates 3 ofthe casing are made the same as in Figure l, but instead of usingpacking rings I5 and I6, laminated as shown in Fig. l, a single thickring is-used between the part! and each end plate 3. ThisI of thecasing' constitute,

This is highly important from a description, the labyrinth ring isdesignated 3l and is divided diametrically into two sections as shown inFig. l0. The inner periphery of each ring is channeled to produce acastellated cross section complementary to and adapted to intert withthe corresponding flange 30 to produce the labyrinth packing. Each ring,moreover, is provided with holes 32 through which bolts 33 may be passedto bolt the rings 30 between the end plates 3 and the main casting I. Byvirtue of these bolts, the parts are secured together and the sectionsof the ring are main-` tained in assembled relation. The purpose ofusing a split ring 3| as described is to permit assembly of the partswhere the flanges 30 are made solid.

The accompanying drawings disclose the invention in its preferredpractical form, but the invention is to be understood as fullycommensurate with the appended claims.

Having thus fully described the invention, what I claim as new anddesire to secure by Letters Patent is:

1.. In an assembly of the character described, a stationary casinghaving coaxial annular recesses of castellated cross section in theopposite ends thereof, an intermediate portion of the casingconstituting an eccentrically positioned chamber having inlet and outletpassages, a rotor positioned within said chamber and mounted to rotatecoaxially of said recesses, flanges of castellated cross section on theends of said rotor interfitting with said recesses, but free fromcontact with the walls of said recesses, said rotor having radialpockets and the flanges having juxtaposed radial channelsin their innerfaces,

and vanes supported for radial movement in said pockets and channels,said vanes being positioned ternately small andA large relatively closeto one another to divide the chamber -into a large number of relativelysmall pockets, the opposing surfaces of the intertted -castellatedportions of the flanges and recesses being parallel to or coaxial withone another and -age or by-passing of pressure from or between theseveral pockets of the rotor is precluded.

2. In an assembly of the character described, a casing provided withcircular end portions and with an intermediate eccentrically disposedcylindrical portion, al rotor positioned within the casing and mountedfor rotation coaxally with the circular end portions of the latter, saidrotor being provided at its opposite ends with flanges, said flangeshaving packing ribs of aldiameter and the corresponding portions of thecasing comprising packing ribs of alternate .large and small internaldiameter complementary to and intermeshing with the pac 'ng ribs of therotor, and spaced therefrom a distance small enougl -to holdcompression, but free froml contact therewith to form a labyrinthpacking at both rotor flanges, and vanes interposed between the rotorand the intermediate portion of the casing and extending between theflanges of the rotor, the rotor being provided with radial pockets andthe spaced apart a substantially uniform distancev tween the rotor andthe flanges having registering radial channels, said vanes beingsupported for radial sliding movement in said pockets and channels, saidpacking ribs being spaced axially and radially a substantially uniformdistance.

3. In an assembly of the character a casing provided with circular endportions, the adjacent e'nd walls .of which occupy parallel planes andsaid casing having an intermediate eccentric cylindrical portion, arotor positioned within the casing and mounted for rotation coaxially ofsaid circular end portions, said rotor being provided at'its oppositeends with flanges positioned in said circular end portions with theadjacent faces of said flanges occupying parallel planes and arranged inclose fitting but noncontacting relation with said adjacent walls of thecircular end portions, vanes interposed between the rotor and theintermediate portion of the casing and extending between the flanges ofthe rotor,.the rotor being provided with radial pockets and the angeshaving registering radial channels with the vanes supported for radialsliding movement in said pockets and channels to divide the interior of-the intermediate portion of the casing into a succession of chambers,said circular end portions'of the casing being provided with spacedapart inwardly extending ribs and said flanges being provided withspaced apart outwardly extending ribs interfltting with the ribs of thecircular portions in close fitting but non-contacting relation with asubstantially uniform spacing between the ribs throughout thecastellated joint thus formed, whereby excessive axial orcircumferential leakage or ;bypassing described.'

of pressure from or between the-several chambers of the rotor isprecluded.

4. In an assembly of the character described, a casing provided withcircular end portions, the adjacent end walls of which occupy parallelplanes and said casing having an intermediate eccentric cylindricalportion, a rotor positioned within the casing and mounted for rotationcoaxially of said circular end portions, said rotor bein-g provided atits opposite ends with flanges positioned in said circular end portionswith the adjacent facesof said ilanges occupying parallel planes andarranged in close fitting but noncontacting relation with said adjacentwalls of the circular end portions, vanes interposed beintermediateportion of the casing and extending between the flanges of the rotor, todivide the interior of the intermediate portion of the casing into asuccession of chambers, said circular end portions'of the casing beingprovided with spaced apart inwardly extending ribs and said anges beingprovided with spaced apart outwardly extending ribs intertting with theribs of the circular portions in close `fitting but non-contactingrelation with a substantially uniform spacing between the ribsthroughout the castellated joint thus formed, whereby excessive axial orcircumferential leakage or by-passing of pressure from or between theseveral chambers of the rotor is precluded.

BORIS BOGOSLOWSKY.

